[rfeenstra]

Jake,  I'll try to answer your questions!  I took the transformer apart by removing the laminatons for the core, then removing the outside wrapping that had the part number on it.  I saved that to put back on the rewound PT to make it look original.  Each layer was then unwound, the wire diameter measured, and the number of turns counted as they were unwound, taking note of exactly how they were wound (ending point, starting point, # of layers, and # of turns per layer - which does vary from layer to layer.) # of turns per layer is not critical so long as the total number of turns is correct.  # of layers and the thicknes of the paper separating them is critical as you don't want to wind up with the bobbin so thick that you cannot slide the E laminations back into the bobbin (I reuse the original bobbin form).  Rewinding is just the unwinding in reverse.  Each layer is separated by a strip of paper and the windings for a completed layer are held in place with a coating of shellac that I use a heat gun on to get it to dry more quickly.  Getting the wire to lay perfectly is a bit tedious but not too bad if you use some form of wire winding contraption.  It takes some patience and practice.  All in all, it is not difficult, just very tedious and time consuming.

The final layer is the power for the filaments of 5 tubes: 4 24's and 1 27.  These are 2.5 volt filaments and draw 1.75 amps per tube.  That's almost 9 amps.  I think they doubled the 14 AWG wire to increase current handling capacity without adding thickness to the bobbin.  In reality, 10 turns of a single wire of 14 AWG would handle the 9 amps, but perhaps they wanted to prevent any heat from being generated in that winding. 

I took a couple of liberties in the number of turns in the primary and HV secondary.  I increased the # of turns in the primary by 10 turns.  This increases the voltage to the 2.5 volt filaments to 2.75 volts and to the rectifier filament from 5 volts to 5.5 volts.  Though this might shorten the life of a tube ever so slightly, it should increase cathode emissions slightly on the weak tubes that will probably be used.  This necessitated that the HV secondary # of windings be increased by about 150 turns to achieve the stated 700 volt output.  Actual voltage measurements bear out the calculations.  Ultimate results will be determined when the radio is complete!

Hope this answers your questions!